Method of conveying fine granular and pulverous material by gaseous means



g- 1968 HERMANN-JOSEF KOPINECK ET AL 3,395,945

METHOD OF CONVEYING FINE GRANULAR AND PULVEROUS MATERIAL BY GASEOUSMEANS Original Filed June 21, 1965 3 Sheets-Sheet l cOnveylng conduit 53312b j cQrr/er gas Aug. 6. 1968 HERMANN-JOSEF KOPINECK ETAL 3,395,945

METHOD OF CONVEYING FINE GRANULAR AND PULVEROUS MATERIAL BY GASEOUSMEANS A Original Filed June 21. 1965 3 Sheets-Sheet 2 ,Vwwrmra 15.1:

Aug. 6, 1968 HERMANN-JOSEF KOPINECK ETAI- 3,395,945

METHOD OF CONVEYING FINE GRANULAR AND PULVEROUS MATERIAL BY GASEOUSMEANS Original Filed June 21. 1965 3 Sheets-Sheet 5 Q o o o Q Q Qseaateams CI I 1 I United States Patent M 4 Claims. (C l. 302-66)ABSTRACT OF THE DISCLOSURE Method of conveying pulverous solid materialwith a gaseous vehicle in which the gas is passed upwardly through thepulverous material thereby entraining the pulverous material thereinwhile simultaneously repetitive shock waves are supplied to the gas andpulverous material to increase the concentration of the pulverousmaterial in the gas.

The present invention relates to a method of conveying fine granular andalso pulverous material, according to which such material is by means ofa carrier gas fluidized in a closed container and by means of a variableconveying pressure caused by the carrier gas introduced in variablequantities into said container discharged from the container andconveyed to and through a feeding line. This application is a divisionalapplication of our co-pending application Ser. No. 465,559, now PatentNo. 3,314,731, filed June 21, 1965.

Of particular interest in this connection is the obtainable conveying ordelivery output which is manifested by the specific quantity of thecarrier gas required for conveying the fine granular or pulverousmaterial and also by the quantity of conveyed material per time unit.

It is an object of the present invention to carry out the delivery ofmaximum quantities of material of the above mentioned type per time unitby means of as little quantities of carrier gas as possible.

It is also an object of the present invention to maintain the valuescharacteristic for the delivery substantially constant during thedelivery operation.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

FIG. 1 diagrammatically illustrates a testing installation employed forcarrying out the method according to the invention;

FIG. 1a illustrates in greater detail the pressure shock emitteremployed in the installation shown in FIG. 1;

FIG. 2 graphically illustrates the test results carried out by theinstallation of FIG. 1.

Aside from the dimensions of the delivery installation, such as size ofthe container, cross section of the conduits, and length of the deliverypath on one hand and the property of the material to be delivered orconveyed, such as particle size, bulk weight, and moisture content onthe other hand, the delivery output depends on the delivery pressure andwithin certain limits also on the respective container content. Testshave proved that for every delivery installation, every material, andevery degree of filling of the container there exists a defined deliverypressure for obtaining an optimum delivery output. When said defineddelivery pressure drops, the quantity of material delivered or conveyedper time unit also 3,395,945 Patented Aug. 6, 1968 drops, whereas whensaid defined delivery pressure increases, the specific conveyingquantity of gas increases while at the same time the quantity ofmaterial delivered per time unit decreases. Therefore, an increase inthe delivery output by increasing the delivery pressure about the saiddefined delivery pressure is not possible.

According to the present invention, additional periodic pressurevariations are produced in the container and preferably in thefluidizing chamber, independently of the change in the delivery pressurebut in conformity with the changing degree of filling of the container.This step has surprisingly resulted in an improvement of the deliveryoutput and, more specifically, by increasing the quantity of materialconveyed per time unit and also by lowering the specific quantity ofcarrier gas. This method furthermore brings about the advantage of amore uniform and more quiet delivery. Moreover, variations in theconsistency of the delivered material no longer affect the delivery to agreat extent, and the material to :be delivered is entirely discharged.

Corresponding periodically repeated pressure variations may beinitiated, for instance, by means of the movement of a piston actingupon the interior of the container or by means of pressure shocksproduced by a diaphragm held by the container walls. The actuation ofthe diaphragm may be effected electrically or mechanically or especiallypneumatically. It is also possible to produce the pressure shocks by acombined pistondiaphragm arrangement.

A number of tests have been carried out for proving the improvement inthe delivery obtained .by the present invention, which tests will now bedescribed in detail. With reference to FIG. 1, this figure shows amaterial conveying device 11 of a standard design with a 1 /2- inchdelivery conduit 12, said device 11 having a capacity of 1,000 liters.Arranged on said device 11 is a mechanical pressure shock or impulseemitter 14 having an output of 3 kilowatts with a sequence of 10pressure shocks per second. This pressure shock emitter 14 which actsupon the fluidizing chamber 13 is flanged to a pipe section 131 in thecontainer lid.

Pressure shock emitter 14 (FIGS. 1, la) comprises a cylinder 16 with apiston displacement chamber 161 and a pressure chamber 162 closed at thetop by a cover 30a forming a part of a housing 30 and connected tocylinder 16 by means of screws 164. Cover 30a has screwed thereinto aconduit 31 adapted to be connected to a source of compressed gas of apressure of 3.5 atmospheres above atmosphcric pressure. Pressure shockemitter 14 furthermore comprises a piston 17 reciprocable in chamber 161and made up of two piston sections 172 and 173, and a piston rod 171.Piston 17 is biased in the downward direction by the pressure fromconduit 31 which acts on the upper face of the piston.

Piston sections 172 and 173 have connected thereto cup sleeves ordiaphragms 18 and 19, respectively. More specifically, diaphragm 18 ison one hand connected to piston section 1721by means of a plate 174 anda nut 175, and on the other hand, clamped between a flange 166 ofcylinder 16 and flange 131 of container 13. Similarly, diaphragm 19 ison one hand connected to piston section 173 by means of a plate 176clamped between a flange 177 of piston rod 171 and piston section 173,and i on the other hand clamped between cover 30a and a flange 167 ofcylinder 16. Thus, piston 17 is by means of diaphragms 18 and 19shielded and sealed with regard to the interior of container 13 andpressure chamber 162.

Piston rod 171 is slidably mounted in bearings 178, 179 in housing 30.The upper end of piston rod 171 has connected thereto a member 32adapted to be actuated by a cam 22 driven by driving means 21 (shown inFIG. 1). Cam disc 22. is so designed that the movement of piston 17 inthe direction toward container 13 is effected in a shock-like manner,whereas the movement in opposite direction is effected relativelyslowly. The said movement of piston 17 toward container 13 is effectedby the pressure on top of the piston delivered thereto by conduit 31.

A housing portion b of housing 30 has screwed thereinto a cup 33encasing a disc 34 and dish spring means 35 clamped between disc 34 andhousing portion 30b. Disc 34 is engaged by a member 36 screwed ontopiston \I'Od 171, the arrangement being such that said dish spring means35 continuously urges said piston rod 171 in upward direction intoengagement with cam 22.

For the above-mentioned tests, the conveying device 11 was filled withfine lime of customary consistency and was subjected to the influence ofa carrier gas introduced at a pressure of about 2.1 atmospheres aboveatmospheric pressure through a conduit 23 provided with a gauge 24adapted to measure the gas quantities and through a sintered plate .27.The material passed through the 25-meterlong conduit 12 which extendsfrom a point adjacent sintered plate 27 through two 90-elbow sections12a and 12b, to a collecting container 26, and was weighed. The majorportion of conduit 12 extends horizontally while forming a loop made upof four 45-elbow sections (not shown). A number of parallel tests werecarried out with a turned-ofi and a turned-on pressure shock emitter 14.The results obtained during these tests are graphically recorded in FIG.2. More specifically, on the "left side of the ordinate there areplotted the results of the tests with turned-off pressure shock emitter,where-as on the right side of said ordinate there are plotted the testresults with turned-on pressure shock emitter 14. The quantity of thematerial delivered per time unit is indicated by solid lines, whereasthe specific quantity of carrier gas is indicated by dash line.

With the above-mentioned test conditions, with the heretofore customarydelivery method, the medium quantity of delivered material wasascertained as amounting to 190 kilograms per minute, and the mediumspecific gas quantity was ascertained as amounting to 18 liters perkilogram of material. On the other hand, with the pressure shockvemitter 14- turned on, the medium quantity of delivered material wasascertained as amounting to 300 kilograms per minute while a mediumspecific gas quantity in the amount of 6 liters per kilogram of materialwas ascertained. This means that with the method according to thepresent invention a 50% improvement was obtained with regard to thequantity of material delivered per time unit, while at the same time thespecific quantity of carrier gas was reduced by 66%.

The sequence of pressure shocks and energy to be selected in eachinstance in conformity with the respective dimensions of the apparatusand the properties of the material to be conveyed can easily beascertained so as to obtain the most favorable effect. The sequence ofthe pressure oscillations is, for instance, with the employed mechanicalpressure shock emitter, determined by the variable speed of rotation ofcam disc 22. The energy is determined 'by the variable piston stroke incombination with the variable pressure acting or resting on piston 17.

It is, of course, to be understood, that the present invention is, by nomeans, limited to the particular method described above, but alsocomprises any modifications Within the scope of the appended claims.

What we claim is:

1. In a method of fluidizing and conveying fine granular and pulveroussolid materials; supporting said materials in a closed container,constantly supplying g s under a uniform pressure to the bottom of thecontainer beneath said material and constantly causing said gas underuniform pressure to flow upwardly intothe material so that the gas willfluidize the material and the material will become entrained in the gas,withdrawing said fluidized material from said container solely from apoint above the lowest level of the said material therein, andadditionally and repetitively supplying from a separate and distinctpower source shock-like pressure variations to the interior of saidcontainer to thereby increase the concentration of the material in thegas withdrawn from the container.

2. A method according to claim 1, in which said additional repetitiveshock-like pressure variations are developed in said container.

3. A method according to claim 1, in which said repetitive shock-likepressure variations are created mechanically in the form of periodicallyrepeated pressure shocks.

4. The method according to claim 1 which includes connecting a chamberto the interior of the container at a point above the said material, andin which each of said pressure shocks is created by slowl drawing gasfrom the container into the chamber, and then suddenly expellin the gasfrom the chamber into the container.

References Cited UNITED STATES PATENTS 1,308,464 7/1919 Westly 302-261,492,352 4/ 1924 Campbell 30226 2,120,003 6/1938 Schanz 302-262,867,478 l/1959 Shale 302-26 3,169,664 2/1965 Meiuicke 222-193 X EVONC. BLUNK, Primary Examiner.

M. L. AJEMAN, Assistant Examiner.

